diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c
index b546736da2e19..caea6885fdbd0 100644
--- a/net/ipv4/gre.c
+++ b/net/ipv4/gre.c
@@ -22,7 +22,7 @@
 #include <net/gre.h>
 
 
-const struct gre_protocol *gre_proto[GREPROTO_MAX] __read_mostly;
+static const struct gre_protocol *gre_proto[GREPROTO_MAX] __read_mostly;
 static DEFINE_SPINLOCK(gre_proto_lock);
 
 int gre_add_protocol(const struct gre_protocol *proto, u8 version)